Assessment of urine sample collection and processing variables for extracellular vesicle-based proteomics.

Extracellular vesicles (EVs) in urine are a promising source for developing non-invasive biomarkers. However, urine concentration and content are highly variable and dynamic, and actual urine collection and handling often is nonideal. Furthermore, patients such as those with prostate diseases have challenges in sample collection due to difficulties in holding urine at designated time points. Here, we simulated the actual situation of clinical sample collection to examine the stability of EVs in urine under different circumstances, including urine collection time and temporary storage temperature, as well as daily urine sampling under different diet conditions. EVs were isolated using functionalized EVtrap magnetic beads and characterized by nanoparticle tracking analysis (NTA), western blotting, electron microscopy, and mass spectrometry (MS). EVs in urine remained relatively stable during temporary storage for 6 hours at room temperature and for 12 hours at 4 °C, while significant fluctuations were observed in EV amounts from urine samples collected at different time points from the same individuals, especially under certain diets. Sample normalization with creatinine reduced the coefficient of variation (CV) values among EV samples from 17% to approximately 6% and facilitated downstream MS analyses. Finally, based on the results, we applied them to evaluate potential biomarker panels in prostate cancer by data-independent acquisition (DIA) MS, presenting the recommendation that can facilitate biomarker discovery with nonideal handling conditions.

Assessing Sodium Intake in Middle-Aged and Older Adults with Elevated Blood Pressure: Validation of Spot Urine Excretion and Dietary Survey-Derived Estimates.

This cross-sectional study evaluated the validity of three alternative methods compared to the gold standard 24-h urine collection for estimating dietary sodium intake, a modifiable risk factor for hypertension, among middle-aged and older adults with elevated blood pressure. These included spot urine collection (using Kawasaki, Tanaka, and INTERSALT equations), 24-h dietary recall, and food frequency questionnaire responses, compared to 24-h urine collection in a subset of 65 participants (aged 50-75 years, 58.5% women, 61.6% hypertensive) from the DePEC-Nutrition trial. The validity of the methods was assessed using bias, the Spearman correlation coefficient (SCC), the intraclass correlation coefficient (ICC), and Bland-Altman analysis. Among the alternative methods, spot urine collection using the Kawasaki equation showed the strongest correlation (SCC 0.238; ICC 0.119, 95% CI -0.079 to 0.323), but it exhibited a significant bias (1414 mg/day, p-value < 0.001) relative to 24-h urine collection. Conversely, dietary surveys had a smaller bias but wider limits of agreement. These findings underscore the complexities of accurately estimating dietary sodium intake using spot urine collection or dietary surveys in this specific population, suggesting that a combination or the refinement of existing methodologies might improve accuracy. Further research with larger samples is necessary to develop more reliable methods for assessing sodium intake in this high-risk group.

Practice variation in urine collection methods among pre-toilet trained children with suspected urinary tract infection: a systematic review.

BACKGROUND: Urinary tract infections (UTIs) are a common cause of acute illness among infants and young children. There are numerous methods for collecting urine in children who are not toilet trained. This review examined practice variation in the urine collection methods for diagnosing UTI in non-toilet-trained children. METHODS: A systematic review was completed by searching MEDLINE (Ovid), Embase (Ovid), CENTRAL (Ovid), PsycInfo (Ovid), CINAHL (EBSCO), and JBI (Ovid) from January 1, 2000 until October 9, 2021 and updated on May 24, 2023. Studies were included if they were conducted in an acute care facility, examined pre-toilet trained children, and compared one urine collection method with another for relevant health care outcomes (such as length of stay in an ED, or re-visits or readmissions to the ED) or provider satisfaction. Two independent reviewers screened the identified articles independently, and those included in the final analysis were assessed for quality and bias using the Newcastle-Ottawa Scale. RESULTS: Overall, 2535 articles were reviewed and 8 studies with a total of 728 children were included in the final analysis. Seven studies investigated the primary outcome of interest, practice variation in urine collection methods to diagnose a UTI. The seven studies that investigated novel methods of urine collection concluded that there were improved health care outcomes compared to conventional methods. Novel methods include emerging methods that are not captured yet captured in clinical practice guidelines including the use of ultrasound guidance to aid existing techniques. Three studies which investigated healthcare provider satisfaction found preference to novel methods of urine collection. CONCLUSIONS: There is significant practice variation in the urine collection methods within and between countries. Further research is needed to better examine practice variation among clinicians and adherence to national organizations and societies guidelines. PROSPERO registration number CRD42021267754.

Clinician and parent views on urine collection in precontinent children in the UK: a qualitative interview study.

OBJECTIVE: To explore the experiences of healthcare professionals (HCPs) and parents of urine collection methods, to identify barriers to successful sampling and what could improve the process. DESIGN: Qualitative research, using individual semistructured interviews with HCPs and parents. The interviews were audiorecorded, transcribed and thematically analysed. SETTING: UK-based HCPs from primary and secondary care settings and parents with experience with urine collection in primary and/or secondary care settings. PARTICIPANTS: HCPs who were involved in aiding, supervising or ordering urine samples. Parents who had experience with urine collection in at least one precontinent child. RESULTS: 13 HCPs and 16 parents were interviewed. 2 participating HCPs were general practitioners (GPs), 11 worked in paediatric secondary care settings (8 were nurses and 3 were doctors). Two parents had children with underlying conditions where frequent urine collection was required to rule out infections.HCPs and parents reported that there were no straightforward methods of urine collection for precontinent children. Each method-'clean catch', urine bag and urine pad-had limitations and problems with usage. 'Clean catch', regarded as the gold standard by HCPs with a lower risk of contamination, often proved difficult for parents to achieve. Other methods had elevated risk of contamination but were more acceptable to parents because they were less challenging. Many of the parents expressed the need for more information about urine collection. CONCLUSIONS: Current methods of urine collection are challenging to use and may be prone to contamination. A new device is required to assist with urine collection in precontinent children, to simplify and reduce the stress of the situation for those involved. Parents are key partners in the process of urine collection with young children. Meeting their expressed need for more information could be an important way to achieve better-quality samples while awaiting a new device.

Can sodium and potassium measured in timed voids be used as reference instruments for validating self-report instruments? Results from a urine calibration study.

BACKGROUND: Sodium and potassium measured in 24-h urine collections are often used as reference measurements to validate self-reported dietary intake instruments. OBJECTIVES: To evaluate whether collection and analysis of a limited number of urine voids at specified times during the day ("timed voids") can provide alternative reference measurements, and to identify their optimal number and timing. METHODS: We used data from a urine calibration study among 441 adults aged 18-39 y. Participants collected each urine void in a separate container for 24 h and recorded the collection time. For the same day, they reported dietary intake using a 24-h recall. Urinary sodium and potassium were analyzed in a 24-h composite sample and in 4 timed voids (morning, afternoon, evening, and overnight). Linear regression models were used to develop equations predicting log-transformed 24-h urinary sodium or potassium levels using each of the 4 single timed voids, 6 pairs, and 4 triples. The equations also included age, sex, race, BMI (kg/m2), and log creatinine. Optimal combinations minimizing the mean squared prediction error were selected, and the observed and predicted 24-h levels were then used as reference measures to estimate the group bias and attenuation factors of the 24-h dietary recall. These estimates were compared. RESULTS: Optimal combinations found were as follows: single voids-evening; paired voids-afternoon + overnight (sodium) and morning + evening (potassium); and triple voids-morning + evening + overnight (sodium) and morning + afternoon + evening (potassium). Predicted 24-h urinary levels estimated 24-h recall group biases and attenuation factors without apparent bias, but with less precision than observed 24-h urinary levels. To recover lost precision, it was estimated that sample sizes need to be increased by ∼2.6-2.7 times for a single void, 1.7-2.1 times for paired voids, and 1.5-1.6 times for triple voids. CONCLUSIONS: Our results provide the basis for further development of new reference biomarkers based on timed voids. CLINICAL TRIAL REGISTRY: clinicaltrials.gov as NCT01631240.

Tubular phosphate transport: a comparison between different methods of urine sample collection in FGF23-dependent hypophosphatemic syndromes.

OBJECTIVES: Tubular maximum phosphate reabsorption per glomerular filtration rate (TmP/GFR) is used to evaluate renal phosphate reabsorption and it is a useful tool for the differential diagnosis of hypophosphatemic syndromes. TmP/GFR is typically calculated from fasting plasma and second morning void urine samples, obtained 2 h after the first void (TmP/GFR 2 h). The purpose of this study was to evaluate if TmP/GFR calculated from 24 h urine collection (TmP/GFR 24 h) can be used as an alternative for TmP/GFR 2 h in patients with urine phosphate wasting. METHODS: We enrolled adult patients with X-linked hypophosphatemia (XLH) or tumor-induced osteomalacia (TIO). All patients underwent blood and urine sample collections, to calculate TmP/GFR 24 h and TmP/GFR 2 h. RESULTS: Twenty patients (17 XLH and 3 TIO), aged 24-78 years, were included. All patients had low TmP/GFR 2 h (0.35 mmol/L, IQR 0.24-0.47 mmol/L) and TmP/GFR 24 h (0.31 mmol/L, IQR 0.22-0.43 mmol/L). The concordance correlation coefficient between TmP/GFR 2 h and TmP/GFR 24 h was 0.86 (95 % CI: 0.69-0.93), with a systematic bias of 0.05 mmol/L (95 % limits of agreement: -0.10 to 0.20). Furthermore, in 70 % (i.e., 14 patients out of 20) and 80 % (i.e., 16 patients out of 20) of cases the difference between TmP/GFR 2 h and TmP/GFR 24 h was within ±30 % and ±35 %, respectively. CONCLUSIONS: Despite TmP/GFR 2 and 24 h show a relatively suboptimal agreement, the difference between the two parameters appears to be small and not clinically significant in the setting of adult patients with FGF23-dependent urine phosphate wasting and secondary hypophosphatemia.

Clean-Catch Urine Specimen More Likely to Be Contaminated After Vaginal Surgery for Pelvic Organ Prolapse.

IMPORTANCE: Accurate diagnosis of urinary tract infection after pelvic organ prolapse (POP) surgery is essential to postoperative care. OBJECTIVE: Our aim was to determine the agreement between the urinalysis of a clean-catch versus a straight catheter urine specimen in women who underwent vaginal surgery for POP. STUDY DESIGN: This was a cross-sectional study evaluating patients after vaginal surgery for POP. A clean-catch and straight catheter urine specimen were collected at routine postoperative appointments. Routine urinalyses and urine cultures were performed for all patients. A urine culture yielding mixed urogenital flora (which includes Lactobacillus species), coagulase-negative staphylococci, and Streptococcus species was considered a contaminated result. The agreement between the characteristics of urinalysis obtained via the clean catch versus the straight catheter at 3 weeks postoperatively was evaluated using weighted κ statistic. RESULTS: Fifty-nine participants enrolled. The agreement between the characteristics of urinalysis obtained via the clean catch versus the straight catheter was poor (κ = 0.018). The urine culture was more likely to be contaminated from the clean-catch urine specimen than from the straight catheter urine specimen (53.7% vs 23.1%).The positive and negative predictive values of leukocyte esterase on clean catch were 22.6% and 100%, respectively. CONCLUSIONS: Diagnosing urinary tract infection based on contaminated urinalyses may lead to antibiotic overuse and misdiagnosis of postoperative complications. Our results can help educate health care partners and discourage the use of clean-catch urine specimens when assessing women who have recently undergone vaginal surgery.

The impact of urine collection method on canine urinary microbiota detection: a cross-sectional study.

BACKGROUND: The urinary tract harbors unique microbial communities that play important roles in urogenital health and disease. Dogs naturally suffer from several of the same urological disorders as humans (e.g., urinary tract infections, neoplasia, urolithiasis) and represent a valuable translational model for studying the role of urinary microbiota in various disease states. Urine collection technique represents a critical component of urinary microbiota research study design. However, the impact of collection method on the characterization of the canine urinary microbiota remains unknown. Therefore, the objective of this study was to determine whether urine collection technique alters the microbial populations detected in canine urine samples. Urine was collected from asymptomatic dogs by both cystocentesis and midstream voiding. Microbial DNA was isolated from each sample and submitted for amplicon sequencing of the V4 region of the bacterial 16 S rRNA gene, followed by analyses to compare microbial diversity and composition between urine collection techniques. RESULTS: Samples collected via midstream voiding exhibited significantly higher sequence read counts (P = .036) and observed richness (P = .0024) than cystocentesis urine. Bray Curtis and Unweighted UniFrac measures of beta diversity showed distinct differences in microbial composition by collection method (P = .0050, R2 = 0.06 and P = .010, R2 = 0.07, respectively). Seven taxa were identified as differentially abundant between groups. Pasteurellaceae, Haemophilus, Friedmanniella, two variants of Streptococcus, and Fusobacterium were over-represented in voided urine, while a greater abundance of Burkholderia-Caballeronia-Paraburkholderia characterized cystocentesis samples. Analyses were performed at five thresholds for minimum sequence depth and using three data normalization strategies to validate results; patterns of alpha and beta diversity remained consistent regardless of minimum read count requirements or normalization method. CONCLUSION: Microbial composition differs in canine urine samples collected via cystocentesis as compared to those collected via midstream voiding. Future researchers should select a single urine collection method based on the biological question of interest when designing canine urinary microbiota studies. Additionally, the authors suggest caution when interpreting results across studies that did not utilize identical urine collection methods.

Do external urine collection devices reduce contamination in urine samples for women with symptoms of urinary tract infection? A systematic review.

INTRODUCTION: To evaluate the impact of external urine collection devices (UCD) on contamination of urine samples in women with symptoms of urinary tract infection. METHODS: This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched for paired sample studies and controlled trials. Studies comparing UCDs with non-invasive urine collection procedures were considered. RESULTS: Only two studies were found. Neither of the two studies found any difference regarding contamination between specimens collected with the UCDs compared and non-invasive techniques. In the largest study, including 1264 symptomatic women, 18.8% of those allocated to UCDs failed to collect urine samples successfully. CONCLUSIONS: More studies involving women with symptoms of urinary tract infection are needed to produce more robust data on the impact of these devices on urine contamination rates.

Best methods for urine sample collection for diagnostic accuracy in women with urinary tract infection symptoms: a systematic review.

BACKGROUND: Most guidelines recommend a midstream urine (MSU) or a midstream clean-catch (MSCC) sample for urinalysis. However, whether this sample is better than others is still controversial. OBJECTIVES: To assess the most adequate non-invasive method to collect a urine specimen for diagnosing urinary tract infections (UTI) in symptomatic non-pregnant women. METHODS: This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched paired sample studies and controlled trials. Studies comparing MSCC, MSU without cleaning, first-void urine, and random voiding samples were considered. Studies evaluating invasive methods were excluded. The main outcome was diagnostic accuracy of urine cultures. Contamination rates were evaluated. The risk of bias tool for systematic reviews on diagnostic accuracy (QUADAS-2) was assessed. RESULTS: Six studies including 1,010 patients were evaluated. Only two studies used paired samples. No study was considered as having low risk of bias. There was no difference in contamination for MSU specimens collected with or without cleansing and between random void urine collection and MSCC. In one study comparing first-void urine with MSU samples, the contamination rate was lower in the latter, but the gold standard of urine culture was only used for one sampling collection. CONCLUSIONS: To the best of our knowledge, this systematic review is the first to assess the evidence available from different exclusively non-invasive urine sampling. Despite being widely recommended, our review did not find consistent evidence that asking women to provide midstream samples with or without cleansing is better.

Urine is one type of specimen that can be easily collected from a patient. Urinalysis testing can give the doctor valuable information about the presence of an infection in the urine and the type of microorganism causing this infection. The physician can also use the information from urine testing to diagnose and treat other diseases. The collection of the mid-stream of the urination has always been advocated. However, this recommendation has never been proven with good quality studies, and the results of the studies carried out so far have been controversial. In a systematic review, we recently determined that the use of any specimen during urination is as good as midstream collection when patients are requested to provide a urine sample and in terms of quality even specimens collected without proper cleansing are also comparable to mid-stream collection with cleansing. In the present systematic review, we evaluated the most adequate non-invasive method to collect a urine specimen for diagnosing urinary tract infections in symptomatic non-pregnant women. We identified only six studies comparing different urine sampling techniques and we did not observe any difference regarding the quality of the urine between them.

Urine collection methods in precontinent children treated at the paediatric emergency department.

AIM: To describe the urine collection methods used in precontinent children presenting at the Paediatric Emergency Department (PED) and compare results and contamination rates. METHODS: Retrospective observational cohort study that included 1678 urine cultures collected in infants <24 months of age between January 2016 and December 2019. Urine cultures were compared based on collection technique, sex and patient age. RESULTS: In total, 60.4% of samples were collected by clean-catch urine collection (CCUC), 26.4% by urethral catheterisation (UC) and 13.2% by urine bag (UB). Contamination rates were 2.9% (95% CI 1.3, 4.4) for UC, 11.3% (95% CI 9.3, 13.2) for CCUC and 23.4% (95% CI 17.8, 29.0) for UB. Significant differences in contamination rates were found between UC and CCUC in the 6-12-month age group (1.9% [95% CI 0.0-4.0] versus 12.0% [95% CI 7.2-16.8] [p < 0.0009]), and between UC and UB for all ages. CONCLUSIONS: CCUC is the most common method for urine culture collection in infants <24 months of age at the PED in our centre. UC has the lowest contamination rates, but significant differences were only observed between CCUC and UC in the 6-12-month age group. CCUC is a non-invasive alternative for urine collection in infants.

Estimating population level 24-h sodium excretion using spot urine samples in older adults in rural South Africa.

BACKGROUND: South Africa has introduced regulations to reduce sodium in processed foods. Assessing salt consumption with 24-h urine collection is logistically challenging and expensive. We assess the accuracy of using spot urine samples to estimate 24-h urine sodium (24hrUNa) excretion at the population level in a cohort of older adults in rural South Africa. METHODS: 24hrUNa excretion was measured and compared to that estimated from matched spot urine samples in 399 individuals, aged 40-75 years, from rural Mpumalanga, South Africa. We used the Tanaka, Kawasaki, International Study of Sodium, Potassium, and Blood Pressure (INTERSALT), and Population Mean Volume (PMV) method to predict 24hrUNa at the individual and population level. RESULTS: The population median 24hrUNa excretion from our samples collected in 2017 was 2.6 g (interquartile range: 1.53-4.21) equal to an average daily salt intake of 6.6 g, whereas 65.4% of participants had a salt excretion above the WHO recommended 5 g/day. Estimated population median 24hrUNa derived from the INTERSALT, both with and without potassium, showed a nonsignificant difference of 0.25 g (P = 0.59) and 0.21 g (P = 0.67), respectively. In contrast, the Tanaka, Kawasaki, and PMV formulas were markedly higher than the measured 24hrUNa, with a median difference of 0.51 g (P = 0.004), 0.99 g (P = 0.00), and 1.05 g (P = 0.00) respectively. All formulas however performed poorly when predicting an individual's 24hrUNa. CONCLUSION: In this population, the INTERSALT formulas are a well suited and cost-effective alternative to 24-h urine collection for the evaluation of population median 24hrUNa excretion. This could play an important role for governments and public health agencies in evaluating local salt regulations and identifying at-risk populations.

A Method for Estimating 24 h Urinary Sodium and Potassium Excretion by Spot Urine Specimen in Stroke Patients.

Spot urine specimens have been used to estimate 24 h urinary sodium (Na) excretion (24UNaV) and potassium (K) excretion (24UKV). However, the validity is limited for 24UNaV and unknown for 24UKV in stroke patients, using the existing formulas. Herein, we developed and validated a new formula for 24UNaV and 24UKV by spot urine specimens in stroke patients. Spot and 24 h urine samples were collected from 970 stroke patients. The models of 24UNaV and 24UKV were developed using stepwise multivariate linear regression in 689 patients. The performance of different formulas was internally validated in 281 patients at the population and individual levels. The obtained new formulas were: (1) estimated 24UNaV (mmol/day): -0.191 × Age + 4.349 × BMI + 0.229 × SpotNa + 1.744 × SpotNa/Spot creatinine (Cr) + 41.492 (for male); -1.030 × Age + 2.011 × BMI + 0.143 × SpotNa + 1.035 × SpotNa/SpotCr + 147.159 (for female); and (2) estimated 24UKV (mmol/day): -0.052 × Age + 0.410 × BMI + 0.031 × SpotK + 33.280 × Ln (spotK/spot Cr) - 5.789 × Ln (spotNa/spot Cr) - 1.035 (for male); -0.235 × Age + 0.530 × BMI + 0.040 × SpotK + 30.990 × Ln (spot K/spot Cr) - 7.837 × Ln (spotNa/spotCr) + 4.318 (for female). The new formula obtained the lowest mean bias (5.17 mmol/day for 24UNaV and 0.85 mmol/day for 24UKV) and highest proportion at the cutoff under the ±30% level for the estimation of 24UNaV (59.43%) and 24UKV (70.11%). The new formula provides a meaningful exploration to estimate 24UNaV and 24UKV in stroke patients by using spot urine specimens.

Validation of salt intake measurements: comparisons of a food record checklist and spot-urine collection to 24-h urine collection.

OBJECTIVE: Monitoring population salt intake is operationally and economically challenging. We explored whether a questionnaire assessment and a prediction of Na intake from spot-urine could replace or complement the recommended measurement of Na in 24-h urine (24-h U). DESIGN: Compare the agreement of a Na-specific food record checklist (FRCL) and a late-afternoon spot-urine measurement (PM-spot) with 24-h U measurement in estimating Na intake at group level. Each participant's use of these methods extended over 3 d. Agreement was assessed using mean (95 % CI) differences, linear regression models and Bland-Altman plots. SETTING: The validation study was part of a 1-year workplace intervention trial to lower salt intake in Switzerland. PARTICIPANTS: Seventy women and 71 men, aged 21-61 years, completed three FRCL, and acceptable PM-spot and 24-h U samples at baseline (April-October 2015). RESULTS: Mean Na intake estimates varied slightly across methods (3·5-3·9 g/d). Mean Na intake differences from 24-h U were 0·2 (95 % CI (0, 0·5)) g/d for FRCL and 0·4 (95 % CI (0·2, 0·6)) g/d for PM-spot. Linear regression models and Bland-Altmann plots more clearly depicted differences by sex and discretionary salt use. CONCLUSIONS: Although 24-h U remains the best reference method for monitoring Na intake at the population level, PM-spot and FRCL might be more practical instruments for frequent, periodic Na intake assessments. Population-specific prediction models to estimate 24-h U could be developed and evaluated.

The position during urine sample collection from young precontinent children through a bag does not limit contamination rates: Results from a randomized controlled trial: Does infant position influence quality of urine collection?

AIM: Despite its limitation, bag collection is still widely used for a preliminary urine screening test in non-toilet-trained children suspected of febrile urinary tract infection. A previous study conducted by our group raised the hypothesis that the absence of direct contact between urine and the perinea during urine collection could limit urine contamination by perineal flora. The aim of this study was to evaluate the impact of the patient's position during urine collection (upright standing position versus free position) on the rate of contaminated urine samples in non-toilet-trained children with suspected febrile urinary tract infection. METHODS: This prospective, randomized, controlled study took place in seven pediatric emergency departments. Two groups were compared: the intervention group (infants held in an upright standing position during urination) and the control group (free position during urination). RESULTS: Among the 800 pediatric patients randomized to the study, 124 had a urine culture, 60 in the intervention group and 64 in the control group. Among the 124 urine cultures, 12 (9.7%) were contaminated: eight (13.3%) in the intervention group and four (6.3%) in the control group (p = 0.1824). CONCLUSION: The results show that the patient's position does not have a significant impact on the quality of urine samples collected by bag.

Efficacy of bladder stimulation techniques for urine collection from infants: a systematic review and metaô€€Žanalysis. / Eficacia de las técnicas de estimulación de la micción para la recogida de orina en el lactante: revisión sistemática y metanálisis.

OBJECTIVES: Collecting a urine sample from an infant is one of the most frequently performed emergency department procedures. We aimed to evaluate noninvasive bladder stimulation techniques to obtain urine samples from infants. MATERIAL AND METHODS: Systematic review and meta-analysis of published experimental and observational studies indexed in MEDLINE (PubMed Central); the Cumulative Index of Nursing and Allied Health Literature (CINAHL); the Ibero-American index, CUIDEN; and Embase. Eligible studies had to have assessed the success rate of a technique, time until urination, level of acceptance, and risk of contamination. Comparison of a stimulation technique to nonstimulation was not necessary. RESULTS: We selected 15 studies enrolling newborns or older infants. The setting was usually an emergency department. The probability of success was 2.4-fold higher with stimulation than without it (relative risk, 2.47; 95% CI, 1.84-3.31; I2, 0%) in 2 studies. The rate of success was higher in newborns (81%; 95% CI, 72.9%-89.1%) in 6 studies totaling 331 cases (I2, 73.2%) than in older infants (51.5%; 95% CI, 35.3%-67.7%) in 9 studies with 809 cases (I2, 96.4%). The mean time required to obtain a sample was 83 (95% CI, 65-101) seconds in 10 studies (I2, 94.3%). The stimulation technique of Herreros had the highest success rate (68.4%; 95% CI, 56.2%-80.7%; I2 95,1%). CONCLUSION: New stimulation techniques for taking urine samples from infants are useful, especially in newborns. Advantages are the short time to urination, the high success rate, and the possibility of lowering the infant's levels of stress and pain.

OBJETIVO: La recogida de orina en el lactante constituye uno de los procedimientos más habituales de los servicios de urgencias. Presentamos una evaluación de las técnicas de estimulación de la micción en lactantes para la recogida no invasiva de orina. METODO: Revisión sistemática con metanálisis de estudios experimentales y observacionales publicados (PubMed, CENTRAL, CINAHL, Cuiden y EMBASE) que evalúen la tasa de éxito, el tiempo hasta la micción, el grado de aceptación y el riesgo de contaminación, en comparación o no con técnicas sin estimulación. RESULTADOS: Seleccionamos 15 estudios que incluían recién nacidos y lactantes en su mayoría atendidos en servicios de urgencias. La probabilidad de éxito es 2,4 veces mayor (RR 2,47; IC 95%: 1,84 a 3,31; 2 estudios, 234 casos; I2 0%) con estimulación que sin ella. La tasa de éxito es mayor en los recién nacidos con un 81% (IC 95% 72,9 a 89,1%; 6 estudios; 331 casos; I2 73,2%) que en los lactantes, con 51,5% (IC 95% 35,3 a 67,7%; 9 estudios; 809 casos; I2 96,4%). El tiempo medio requerido es de 83 segundos (IC 95%: 65 a 101; 10 estudios; I2 94,3%). La técnica con la mayor tasa de éxito es la de Herreros con un 68,4% (IC 95% 56,2 a 80,7%; I2 95,1%). CONCLUSIONES: Las nuevas técnicas de estimulación de la micción son una buena alternativa para la recogida de orina, especialmente para recién nacidos. Además de reducir el tiempo y aumentar el éxito de la captura, puede disminuir el estrés y el dolor del niño.

Design of automatic urine collection system for medical system applications.

BACKGROUND: The results of urine tests are often affected by improper midstream urine collection time, urine spilling, and urine pollution, all of which can lead to an increase in the test error. OBJECTIVE: To solve this problem, aiming at improving the toilet environment at the hospitals and public physical examination centers, this paper designs an automatic urine collection system. It can automatically adjust the position of the urine cup with an infrared remote controller, or manually, adjust the position of the urine cup in special situations according to the needs of the user. It also has an alarm function. METHODS: The overall size and shape are designed based on the squatting pan, suitable for disposable plastic urine cups of different shapes and sizes. It can realize the automatic collection of midstream urine, manual collection in exceptional cases, emergency stops, and rescue calls. RESULTS: Through the trial survey, there was a significant difference between the statistical results of using the device and not using the device (t= 13.937, P= 0.000). 96% of the subjects thought that the design of the system was reasonable, 22% thought that it was inconvenient to use, and 91.7% of the medical staff thought that the system met the sampling requirements. CONCLUSIONS: Therefore, the trial evaluation is satisfactory, and the proposed collection system is suitable for use in hospitals at all levels and public health examination centers with a large amount of inspection.

Women's information needs around urine testing for urinary tract infections: a qualitative study.

BACKGROUND: Urinary tract infection (UTI) is one of the commonest bacterial infections in general practice, with urine testing a frequent feature of its management. Urinary dipsticks are widely used, with urine culture the reference standard test. To avoid contamination, patients are advised to discard the first part of the urine stream, retaining the midstream part for the sample. This process, however, can be challenging both to explain and to perform. There is a lack of literature investigating women's perceptions and understanding of urine sampling. AIM: To explore women's understanding of urine collection, sample contamination, and how information from samples informed UTI management. DESIGN AND SETTING: Qualitative study embedded in a UK randomised controlled trial (RCT) of urinary collection devices (UCDs) among women attending primary care with a suspected UTI. METHOD: Semi-structured telephone interviews were conducted with 29 women participating in the RCT. Interviews were transcribed and thematically analysed. RESULTS: Participants were not always aware about what midstream samples were and why they were preferable. They also lacked understanding about how urine samples may be contaminated, and sources of contamination. Participants experienced variability in the information received following analysis of their sample. CONCLUSION: Provision of clear information could help provide better urine samples, aiding the diagnosis of UTIs, presenting results with greater clarity, and creating less need for repeat samples. Sharing of information derived from uncontaminated samples may also support better UTI management, helping to reduce unnecessary prescribing and antibiotic resistance.

Chlorhexidine skin cleaning to reduce clean-catch urine contamination in infants: A pilot study.

OBJECTIVE: Clean-catch urine (CCU) samples are frequently contaminated. Our aim was to determine if cleaning with 0.1% chlorhexidine before CCU is a safe and feasible method to reduce contamination. METHODS: Prospective interventional pilot study. Children 1-24 months underwent perigenital skin cleaning with 0.1% chlorhexidine. Primary outcome was contamination rate, and secondary outcomes were parent and clinician satisfaction with the procedure. RESULTS: Twelve of 54 urine samples were contaminated (22%, 95% CI 13-35). Over 90% of parents and clinicians were either 'satisfied' or 'very satisfied'. No adverse events were recorded. CONCLUSION: Cleaning with chlorhexidine solution before CCU is safe and feasible.